Thermostats that are used in offices, restaurants, hotels, and similar types of location are subject to extensive setpoint temperature changes by unauthorized individuals. In some types of installations, it is necessary to place a locked cover over a thermostat to maintain a proper temperature setting. In other locations it is desirable to allow the persons having access to the thermostat to make limited temperature changes. This is particularly true in hotels and motels.
It has been common in this type of thermostat to provide adjustable stops. Two stops are placed in the thermostat and allow a temperature control lever to be moved between two pre-established limits. This typically has been done by the use of a screwdriver adjustment wherein the stop is mechanically locked down in its desired position. This tends to lead to a situation in which convenient changes of the stops cannot be made without tools. Also, this structure can be accidentally damaged if the screws are over tightened. Further, the amount of change of the setting of the stops is a matter of judgement, or must be calibrated with a separate temperature scale.